THE LOWER FOEMS OF LIFE. 



39 



developed into a Difflugia ; nor does the portion of the latter ever 

 become an Arcella. This is a much more important fact, as bearing 

 upon the great question of the origin of species, than appears at 

 first sight. 



The stamp of individuality is affixed to the speck of sarcode by 

 its Creator for ever. We shall presently find the Amoeba among 

 the earliest animals in time ; first, in the oldest known rock ; then 

 a mighty architect in the secondary geological epoch ; and thirdly, 

 unaltered and unchanged in the stagnant ditch or the great ocean 



Fig. 40. 



Fig. 41. 



Fig. 42. 



Fig. W.Vifflugm globosa, highly magnified (after Ehrenberg), a, test 6, pseudopodia. 

 Fig. 41. Arcella vulgaris. 



Fig. SZ. Gromia oviformis, highly magnified (after Schultze). a, test b, diatom caught in 

 pseudopodia c, sarcode covering outside of test. 



of these our own days. After Arcella I would direct attention to 

 Fig. 42, which shows a typical form of the genus Gromia, sending forth 

 its long processes, and forming a net, just as we saw was done by 

 the magnificent L. Wageneri. Observe that the test is also covered 

 by an extension of the pseudopodial sarcode, and from this other 

 filaments are sent out. 



